JP3867065B2 - Electron emitting device and light emitting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electron-emitting device and a light-emitting device that output secondary electrons emitted from a substance that serves as an emitter.
[0002]
[Prior art]
Recently, an electron-emitting device has a cathode electrode and an anode electrode, and is applied to various applications such as a field emission display (FED) and a backlight. When applied to the FED, a plurality of electron-emitting devices are two-dimensionally arranged, and a plurality of phosphors for these electron-emitting devices are arranged with a predetermined interval.
[0003]
Conventional examples of this electron-emitting device include, for example, Patent Documents 1 to 5. Moreover, although it is considered that the emitter portion is made of a dielectric, various theories are described in the following Non-Patent Documents 1 to 3 as electron emission from the dielectric.
[0004]
[Patent Document 1]
JP-A-1-315333
[Patent Document 2]
JP 7-147131 A
[Patent Document 3]
JP 2000-285801 A
[Patent Document 4]
Japanese Patent Publication No.46-20944
[Patent Document 5]
Japanese Examined Patent Publication No. 44-26125
[Non-Patent Document 1]
Yasuoka, Ishii, "Pulsed electron source using a ferroelectric cathode" Applied Physics Vol.68, No.5, p546-550 (1999)
[Non-Patent Document 2]
V.F.Puchkarev, G.A.Mesyats, On the mechanism of emission from the ferroelectric ceramic cathode, J.Appl.Phys., Vol. 78, No. 9, 1 November, 1995, p. 5633-5637
[Non-Patent Document 3]
H.Riege, Electron emission ferroelectrics-a review, Nucl. Instr. And Meth. A340, p. 80-89 (1994)
[0005]
[Problems to be solved by the invention]
However, the above-described conventional electron-emitting device has a problem that the electron emission is not stable, the number of electron emission is up to about tens of thousands, and the practicality is poor. That is, conventionally, the effect of the electron-emitting device having the emitter portion has not been found.
[0006]
The present invention has been made in consideration of such problems, and by using secondary electrons emitted from a substance serving as an emitter as an output, it is possible to extend the lifetime of electron emission and improve reliability. It is an object to provide an electron-emitting device and a light-emitting device that can be used.
[0007]
Another object of the present invention is to provide an electron-emitting device and a light-emitting device that can be applied to various applications and can contribute to the spread of electron-emitting devices.
[0008]
[Means for Solving the Problems]
  FirstAn electron-emitting device according to the present invention is characterized in that a primary electron collides with a substance serving as an emitter, a secondary electron is emitted from the material serving as an emitter, and the secondary electron is output.TheIn this case, an electron beam may be obtained by accelerating secondary electrons emitted from the emitter material by an electric field formed on the emitter material.Yes.
[0009]
The secondary electrons described here gain energy from the Coulomb collision of the primary electrons and jump out of the substance that becomes the emitter, Auger electrons, and near the surface of the substance that the primary electron becomes the emitter. Includes all scattered (backscattered electrons).
[0010]
  FirstIn the present invention, by using the secondary electrons emitted from the substance serving as the emitter as an output, it is possible to extend the life of the electron emission and improve the reliability. This leads to the fact that the electron-emitting device according to the present invention can be applied to various applications, and can contribute to the spread of the electron-emitting device.
[0011]
  The emitter material is a dielectric.Consists of.In this case, the substance serving as the emitter can be composed of any one of a piezoelectric material, an antiferroelectric material, and an electrostrictive material.The Further, the first electrode and the second electrode may be formed on the same surface of the substance that becomes the emitter.
[0012]
  In addition, when the substance that becomes the emitter is made of a dielectric, a first electrode is formed on the substance that becomes the emitter, and a second electrode is formed on the substance that becomes the emitter separately from the first electrode. The primary electrons are obtained by applying a driving voltage between the first electrode and the second electrode to reverse the polarization of the emitter material.The
[0013]
  Here, the operation of the electron-emitting device according to the present invention using a dielectric as the emitter material will be described. First, when a driving voltage is applied between the first electrode and the second electrode, at least a part of the substance serving as an emitter is inverted in polarity, and the potential of the first electrode is lower than that of the second electrode. From the neighborhood ofPrimaryElectrons will be releasedTheThat is, by this polarization reversal, a local concentrated electric field is generated between the first electrode and the positive side of the dipole moment in the vicinity thereof, whereby primary electrons are drawn from the first electrode, and the first electrode is extracted. Primary electrons extracted from the electrode collide with the emitter material, and secondary electrons are emitted from the emitter material.The
[0014]
  When the electron-emitting device has the triple point of the first electrode, the emitter substance, and the vacuum atmosphere, primary electrons are drawn from the portion near the triple point of the first electrode, and the electron is extracted. The primary electrons collide with the emitter material, and secondary electrons are emitted from the emitter material.TheNote that when the thickness of the first electrode is extremely thin (˜10 nm), electrons are emitted from the interface between the first electrode and the substance to be the emitter.
[0015]
Since electrons are emitted according to such a principle, electron emission is stably performed, and the number of electron emission times can be realized over 2 billion times, which is highly practical. In addition, since the amount of emitted electrons increases almost in proportion to the level of the voltage applied between the first electrode and the second electrode, there is an advantage that the amount of emitted electrons can be easily controlled.
[0016]
  AndAccording to the first inventionWhen the electron-emitting device is used as, for example, a pixel of a display, a third electrode is disposed at a position facing the first electrode above the emitter material, and the third electrode is a phosphor. Will be applied. In this case, most of the emitted secondary electrons are led to the third electrode to excite the phosphor, and are realized as phosphor emission outside. Of course, a third electrode for forming an electric field between the emitter and the substance serving as the emitter may be disposed, and an electron beam may be emitted to the third electrode. YoYes.
[0017]
  Also,FirstIn the present invention, when the distance between the first electrode and the second electrode is d and the voltage between the first electrode and the second electrode is Vak, it is applied to the substance that becomes the emitter. In addition, polarization inversion may be performed by an electric field E represented by E = Vak / d.Yes.In this case, the voltage Vak is preferably less than the breakdown voltage of the emitter material.Yes.At this time, it is preferable to set the distance d between the first electrode and the second electrode so that the absolute value of the voltage Vak between the first electrode and the second electrode is less than 100V. BetterYes.
[0018]
  Next, the secondThe light emitting device according to the present invention isAccording to the first aspect of the present invention described aboveAn electron-emitting device;Of the electron-emitting deviceDisposed from the substance serving as the emitter, comprising an electrode for forming an electric field between the substance serving as the emitter and the phosphor serving as the emitter, and a phosphor formed on the electrode. The secondary electrons are caused to collide with the phosphor to excite the phosphor to emit light.The
[0019]
Thus, by using the secondary electrons emitted from the substance serving as the emitter as the light emission source, it is possible to extend the life of the electron emission (light emission) and improve the reliability. Moreover, it can be applied to various applications and can contribute to the spread of light-emitting elements.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the electron-emitting device and the light-emitting device according to the present invention will be described with reference to FIGS.
[0021]
First, as shown in FIG. 1, the electron-emitting device 10 </ b> A according to the first embodiment includes a plate-like emitter section (substance that becomes an emitter) 16 and a first emitter formed on the surface of the emitter section 16. It has an electrode (cathode electrode) 18 and a second electrode (anode electrode) 14 formed on the back surface of the emitter section 16.
[0022]
A drive voltage Va from the pulse generation source 20 is applied between the cathode electrode 18 and the anode electrode 14 via a resistor R1. In the example of FIG. 1, the anode electrode 14 is connected to GND (ground) via the resistor R <b> 2 to make the potential of the anode electrode 14 zero. Of course, the potential is set to a potential other than zero potential. It doesn't matter. The drive voltage Va is applied between the cathode electrode 18 and the anode electrode 14 through a lead electrode 19 extending to the cathode electrode 18 and a lead electrode 15 extending to the anode electrode 14 as shown in FIG.
[0023]
When this electron-emitting device 10A is used as a light emitting device or a display pixel, a transparent plate 21 made of, for example, glass or acrylic is disposed above the cathode electrode 18, and the back surface of the transparent plate 21 (the cathode electrode 18). The collector electrode 22 made of, for example, a transparent electrode is disposed on the surface facing the electrode, and a phosphor 24 is applied to the collector electrode 22. A bias voltage source 102 (bias voltage Vc) is connected to the collector electrode 22 via a resistor R3.
[0024]
In addition, the electron-emitting device 10A according to the first embodiment is naturally disposed in the vacuum space. As shown in FIG. 1, the electron emission element 10A has an electric field concentration point A. However, the point A may be a point including a triple point where the cathode electrode 18 / emitter portion 16 / vacuum exists at one point. Can be defined.
[0025]
And the degree of vacuum in the atmosphere is 10²-10^-6Pa is preferred, more preferably 10^-3-10^-FivePa.
[0026]
The reason for selecting such a range is that in low vacuum, (1): there are a lot of gas molecules in the space, so it is easy to generate plasma, and if too much plasma is generated, a large amount of positive ions are generated in the cathode electrode. There is a possibility of causing damage by colliding with 18, and {circle around (2)}: the emitted electrons collide with gas molecules before reaching the collector electrode 22, and the phosphor 24 due to electrons sufficiently accelerated at the collector potential (Vc). This is because excitation may not be sufficiently performed.
[0027]
On the other hand, in high vacuum, electrons are likely to be emitted from the electric field concentration point A, but there is a problem that the support of the structure and the vacuum seal portion become large, which is disadvantageous for miniaturization.
[0028]
Here, the emitter section 16 is made of a dielectric. As the dielectric, a dielectric having a relatively high relative dielectric constant, for example, 1000 or more can be adopted. In addition to barium titanate, such dielectrics include lead zirconate, lead magnesium niobate, lead nickel niobate, lead zinc niobate, lead manganese niobate, lead magnesium tantalate, lead nickel tantalate, Ceramics containing lead antimony stannate, lead titanate, lead magnesium tungstate, lead cobalt niobate, etc., or any combination thereof, those containing 50% by weight or more of these compounds as the main component, or the ceramics In addition to lanthanum, calcium, strontium, molybdenum, tungsten, barium, niobium, zinc, nickel, manganese, etc., or any combination of these, or those appropriately added with other compounds Can do.
[0029]
For example, in a two-component system nPMN-mPT of lead magnesium niobate (PMN) and lead titanate (PT) (where n and m are mole ratios), increasing the PMN mole ratio decreases the Curie point. Thus, the relative dielectric constant at room temperature can be increased.
[0030]
In particular, when n = 0.85 to 1.0 and m = 1.0−n, the relative dielectric constant is preferably 3000 or more. For example, when n = 0.91 and m = 0.09, a relative permittivity of 15000 at room temperature is obtained, and when n = 0.95 and m = 0.05, a relative permittivity of 20000 at room temperature is obtained.
[0031]
Next, in the three-component system of lead magnesium niobate (PMN), lead titanate (PT), and lead zirconate (PZ), besides increasing the molar ratio of PMN, tetragonal and pseudocubic or tetragonal crystals And a composition in the vicinity of a morphotropic phase boundary (MPB) of rhombohedral crystals are preferable for increasing the relative dielectric constant. For example, the relative dielectric constant is 5500 when PMN: PT: PZ = 0.375: 0.375: 0.25, and the relative dielectric constant is 4500 when PMN: PT: PZ = 0.5: 0.375: 0.125. Is particularly preferred. Furthermore, it is preferable to improve the dielectric constant by mixing a metal such as platinum into these dielectrics within a range where insulation can be ensured. In this case, for example, 20% by weight of platinum may be mixed in the dielectric.
[0032]
Further, as described above, a piezoelectric / electrostrictive layer, an antiferroelectric layer, or the like can be used for the emitter section 16. When a piezoelectric / electrostrictive layer is used as the emitter section 16, the piezoelectric / electrostrictive layer is used. For example, lead zirconate, lead magnesium niobate, lead nickel niobate, lead zinc niobate, lead manganese niobate, lead magnesium tantalate, lead nickel tantalate, lead antimony stannate, lead titanate, titanate Ceramics containing barium, lead magnesium tungstate, lead cobalt niobate, etc., or any combination thereof may be mentioned.
[0033]
It goes without saying that the main component may contain 50% by weight or more of these compounds. Among the ceramics, a ceramic containing lead zirconate is most frequently used as a constituent material of the piezoelectric / electrostrictive layer constituting the emitter section 16.
[0034]
Further, when the piezoelectric / electrostrictive layer is composed of ceramics, the ceramics may further include oxides such as lanthanum, calcium, strontium, molybdenum, tungsten, barium, niobium, zinc, nickel, manganese, or any of these. A combination of the above or other compounds as appropriate may be used.
[0035]
For example, it is preferable to use a ceramic containing, as a main component, a component composed of lead magnesium niobate, lead zirconate and lead titanate, and further containing lanthanum or strontium.
[0036]
The piezoelectric / electrostrictive layer may be dense or porous, and in the case of being porous, the porosity is preferably 40% or less.
[0037]
When an antiferroelectric layer is used as the emitter section 16, the antiferroelectric layer is mainly composed of lead zirconate, a component composed mainly of lead zirconate and lead stannate, Furthermore, what added lanthanum oxide to lead zirconate, and what added lead zirconate and lead niobate to the component which consists of lead zirconate and lead stannate are desirable.
[0038]
The antiferroelectric film may be porous. In the case of being porous, the porosity is preferably 30% or less.
[0039]
Furthermore, when strontium bismuthate tantalate is used for the emitter section 16, polarization inversion fatigue is small and preferable. Such a material with low polarization reversal fatigue is a layered ferroelectric compound, (BiO₂)²⁺(A_m-1B_mO_{3m + 1})^2-It is expressed by the general formula. Here, the ions of metal A are Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺, Bi³⁺, La³⁺And the ion of metal B is Ti⁴⁺, Ta⁵⁺, Nb⁵⁺Etc.
[0040]
In addition, the sintering temperature can be lowered by mixing the piezoelectric / electrostrictive / antiferroelectric ceramics with a glass component such as lead borosilicate glass and other low melting point compounds (such as bismuth oxide).
[0041]
In addition, by using a lead-free material for the emitter section 16 and the like, the emitter section 16 is made of a material having a high melting point or transpiration temperature, so that it is difficult to be damaged by the collision of electrons or ions.
[0042]
Here, the magnitude of the thickness d (see FIG. 1) of the emitter section 16 between the cathode electrode 18 and the anode electrode 14 will be described. The voltage between the cathode electrode 18 and the anode electrode 14 (output from the pulse generation source 22). When a drive voltage Va is applied between the cathode electrode 18 and the anode electrode 14 and a voltage appearing between the cathode electrode 18 and the anode electrode 14 is Vak, an electric field E expressed by E = Vak / d The thickness d is preferably set so that polarization inversion is performed. That is, as the thickness d is smaller, polarization inversion can be performed at a lower voltage, and electrons can be emitted by driving at a lower voltage (for example, less than 100 V).
[0043]
The cathode electrode 18 is made of the following material. That is, a conductor having a low sputtering rate and a high evaporation temperature in a vacuum is preferable. For example, Ar⁺The sputtering rate at 600V is 2.0 or less and the vapor pressure is 1.3 × 10^-3A temperature at which Pa becomes 1800 K or higher is preferable, and platinum, molybdenum, tungsten, and the like correspond to this. Also, a conductor having resistance to a high-temperature oxidizing atmosphere, such as a simple metal, an alloy, a mixture of insulating ceramics and a simple metal, a mixture of insulating ceramics and an alloy, etc., preferably platinum, iridium, It is composed of a high melting point noble metal such as palladium, rhodium or molybdenum, an alloy containing silver-palladium, silver-platinum or platinum-palladium as a main component, or a cermet material of platinum and a ceramic material. More preferably, it is made of a material mainly composed of platinum or a platinum-based alloy. Further, carbon and graphite materials such as diamond thin film, diamond-like carbon, and carbon nanotube are also preferably used as the electrode. In addition, about 5-30 volume% is suitable for the ratio of the ceramic material added in electrode material.
[0044]
Furthermore, it is preferable to use a material such as an organometallic paste that can obtain a thin film after firing, such as a platinum resinate paste. Also, oxide electrodes that suppress polarization reversal fatigue, such as ruthenium oxide, iridium oxide, strontium ruthenate, La_1-xSr_xCoO_Three(For example, x = 0.3 or 0.5), La_1-xCa_xMnO_Three, La_1-xCa_xMn_1-yCo_yO_Three(For example, x = 0.2, y = 0.05), or a mixture of these with, for example, a platinum resinate paste is preferable.
[0045]
The cathode electrode 18 is made of the above-described materials using various thick film forming methods such as screen printing, spraying, coating, dipping, coating, and electrophoresis, sputtering, ion beam, vacuum deposition, and ion plating. The film can be formed according to an ordinary film forming method by various thin film forming methods such as chemical vapor deposition (CVD) and plating, and preferably the former thick film forming method.
[0046]
The planar shape of the cathode electrode 18 may be an elliptical shape as shown in FIG. 2, or may be a ring shape like the electron-emitting device 10Aa according to the first modification shown in FIG. Or you may make it comb-tooth shape like 10 Eb of electron-emitting elements which concern on the 2nd modification shown in FIG.
[0047]
By setting the planar shape of the cathode electrode 18 to a ring shape or a comb-like shape, the triple point of the cathode electrode 18 / emitter portion 16 / vacuum which is also the electric field concentration point A increases, and the electron emission efficiency can be improved.
[0048]
The thickness tc (see FIG. 1) of the cathode electrode 18 is preferably 20 μm or less, and preferably 5 μm or less. Therefore, the thickness tc of the cathode electrode 18 may be 100 nm or less. In particular, when the thickness tc of the cathode electrode 18 is extremely thin (10 nm or less) as in the electron-emitting device 10Ac according to the third modification shown in FIG. Electrons are emitted from the interface, and the electron emission efficiency can be further improved.
[0049]
On the other hand, the anode electrode 14 is formed by the same material and method as the cathode electrode 18, but is preferably formed by the thick film forming method. The thickness of the anode electrode 14 is also preferably 20 μm or less, and preferably 5 μm or less.
[0050]
By performing heat treatment (firing treatment) each time the emitter section 16, the cathode electrode 18 and the anode electrode 14 are formed, an integrated structure can be obtained. Depending on the method of forming the cathode electrode 18 and the anode electrode 14, a heat treatment (firing process) for integration may not be required.
[0051]
The temperature related to the firing treatment for integrating the emitter section 16, the cathode electrode 18 and the anode electrode 14 is in the range of 500 to 1400 ° C, preferably in the range of 1000 to 1400 ° C. Further, when the film-shaped emitter portion 16 is heat-treated, it is preferable to perform a firing process while controlling the atmosphere together with the evaporation source of the emitter portion 16 so that the composition of the emitter portion 16 does not become unstable at high temperatures.
[0052]
Alternatively, a method may be employed in which the emitter portion 16 is covered with an appropriate member and fired so that the surface of the emitter portion 16 is not directly exposed to the firing atmosphere.
[0053]
Next, the principle of electron emission of the electron emitter 10A will be described with reference to FIGS. 1 and 6 to 11B. First, as shown in FIG. 6, the drive voltage Va output from the pulse generation source 20 includes a period during which the first voltage Va1 is output (preparation period T1) and a period during which the second voltage Va2 is output (electrons). The release period T2) is one step and the one step is repeated. The first voltage Va1 is a voltage in which the potential of the cathode electrode 18 is higher than the potential of the anode electrode 14, and the second voltage Va2 is a voltage in which the potential of the cathode electrode 18 is lower than the potential of the anode electrode 14. The amplitude Vin of the drive voltage Va can be defined by a value obtained by subtracting the second voltage Va2 from the first voltage Va1 (= Va1-Va2).
[0054]
As shown in FIG. 7, the preparation period T <b> 1 is a period in which the emitter section 16 is polarized by applying the first voltage Va <b> 1 between the cathode electrode 18 and the anode electrode 14. The first voltage Va1 may be a DC voltage as shown in FIG. 6, but one pulse voltage or a pulse voltage may be continuously applied a plurality of times. Here, the preparation period T1 is preferably longer than the electron emission period T2 in order to sufficiently perform the polarization process. For example, the preparation period T1 is preferably 100 μsec or more. This is because the absolute value of the first voltage Va1 for polarization is calculated from the absolute value of the second voltage Va2 for the purpose of preventing power consumption during the application of the first voltage Va1 and damage to the cathode electrode 18. This is because it is set to be small.
[0055]
Further, the first voltage Va1 and the second voltage Va2 are preferably voltage levels at which polarization processing can be reliably performed with positive and negative polarities, for example, the dielectric of the emitter section 16 has a coercive voltage. In this case, the absolute values of the first voltage Va1 and the second voltage Va2 are preferably equal to or greater than the coercive voltage.
[0056]
The electron emission period T <b> 2 is a period in which the second voltage Va <b> 2 is applied between the cathode electrode 18 and the anode electrode 14. By applying the second voltage Va2 between the cathode electrode 18 and the anode electrode 14, as shown in FIG. 8, at least a part of the emitter section 16 is polarized. Here, the portion where the polarization is inverted is not limited to the portion directly below the cathode electrode 18 but also the portion where the cathode electrode 18 is not directly above and the surface is exposed is similar in the vicinity of the cathode electrode 18. Polarization inversion is performed. That is, in the vicinity of the cathode electrode 18, the portion where the surface of the emitter portion 16 is exposed is caused by the seepage of polarization. Due to this polarization reversal, a local concentrated electric field is generated between the cathode electrode 18 and the positive pole side of the dipole moment in the vicinity thereof, whereby primary electrons are drawn from the cathode electrode 18 and drawn from the cathode electrode 18. Primary electrons collide with the emitter section 16 and secondary electrons are emitted from the emitter section 16.
[0057]
When the cathode electrode 18, the emitter section 16, and the vacuum triple point A are provided as in the first embodiment, primary electrons are extracted from the vicinity of the triple point A in the cathode electrode 18, Primary electrons extracted from the triple point A collide with the emitter section 16, and secondary electrons are emitted from the emitter section 16. When the thickness of the cathode electrode 18 is extremely thin (-10 nm), electrons are emitted from the interface between the cathode electrode 18 and the emitter section 16.
[0058]
Here, the operation by applying the negative voltage Va2 will be described in more detail.
[0059]
First, when the second voltage Va2 is applied between the cathode electrode 18 and the anode electrode 14, secondary electrons are emitted from the emitter section 16 as described above. That is, the dipole moment charged in the vicinity of the cathode electrode 18 in the emitter section 16 whose polarization is reversed will extract the emitted electrons.
[0060]
That is, a local cathode is formed in the vicinity of the interface with the emitter portion 16 in the cathode electrode 18, and the + pole of the dipole moment charged in the portion in the vicinity of the cathode electrode 18 in the emitter portion 16 is local. Electrons are extracted from the cathode electrode 18 as a typical anode, and some of the extracted electrons are guided to the collector electrode 22 (see FIG. 1) to excite the phosphor 24 and fluoresce outside. It will be embodied as body light emission. Among the extracted electrons, some of the electrons collide with the emitter section 16, and secondary electrons are emitted from the emitter section 16, and the secondary electrons are guided to the collector electrode 22 to cause the phosphor 24. Will be excited.
[0061]
Here, the secondary electron emission distribution will be described with reference to FIG. As shown in FIG. 10, the majority of secondary electrons have an energy close to 0, and when released from the surface of the emitter section 16 in a vacuum, the secondary electrons move only according to the surrounding electric field distribution. . That is, secondary electrons are accelerated according to the surrounding electric field distribution from a state where the initial velocity is almost 0 (m / sec). Therefore, as shown in FIG. 1, if an electric field Ea is generated between the emitter section 16 and the collector electrode 22, the emission trajectory of the secondary electrons is determined along the electric field Ea. That is, an electron source with high straightness can be realized. Such secondary electrons with a small initial velocity are electrons in the solid that have gained energy by Coulomb collision of the primary electrons and jumped out of the emitter section 16.
[0062]
By the way, as can be seen from FIG.₀Secondary electrons having energy corresponding to are emitted. The secondary electrons are those in which the primary electrons emitted from the cathode electrode 18 are scattered near the surface of the emitter section 16 (reflected electrons). The secondary electrons described in this specification are defined to include the reflected electrons and Auger electrons.
[0063]
When the thickness of the cathode electrode 18 is extremely thin (˜10 nm), the primary electrons emitted from the cathode electrode 18 are reflected at the interface between the cathode electrode 18 and the emitter section 16 and travel toward the collector electrode 22.
[0064]
Here, as shown in FIG. 8, the electric field strength E at the electric field concentration point A is shown._AIs the potential difference between the local anode and the local cathode, V (la, lk), and the distance between the local anode and the local cathode, d_AWhen E_A= V (la, lk) / d_AThere is a relationship. In this case, the distance d between the local anode and the local cathode_AIs very small, the electric field strength required for electron emission E_ACan be easily obtained (electric field strength E_A(Indicated by a solid arrow in FIG. 8). This leads to lowering of the voltage Vak.
[0065]
Then, if the electron emission from the cathode electrode 18 proceeds as it is, the constituent atoms of the emitter section 16 which are evaporated and floated by Joule heat are ionized into positive ions and electrons by the emitted electrons, and the electrons generated by this ionization are generated. Further ionizes constituent atoms of the emitter section 16 and the like, so that the number of electrons increases exponentially, and when this proceeds and the electrons and positive ions are neutral, local plasma is formed. It is conceivable that secondary electrons also promote the ionization. It is also conceivable that the positive electrode generated by the ionization collides with, for example, the cathode electrode 18 to damage the cathode electrode 18.
[0066]
However, in the electron-emitting device 10A according to the first embodiment, as shown in FIG. 9, the electrons drawn from the cathode electrode 18 become the positive pole of the dipole moment of the emitter section 16 existing as the local anode. As a result, charging of the surface of the emitter section 16 in the vicinity of the cathode electrode 18 to the negative polarity proceeds. As a result, the electron acceleration factor (local potential difference) is relaxed, the potential leading to the secondary electron emission does not exist, and the negative charge on the surface of the emitter section 16 further proceeds.
[0067]
Therefore, the positive polarity of the local anode at the dipole moment is weakened, and the electric field strength E between the local anode and the local cathode is reduced._A(Electric field strength E_AIs indicated by a broken arrow in FIG. 9), the electron emission is stopped.
[0068]
That is, as shown in FIG. 11A, when the driving voltage Va applied between the cathode electrode 18 and the anode electrode 14 is set such that the first voltage Va1 is, for example, + 50V and the second voltage Va2 is, for example, −100V, electron emission is performed. The voltage change ΔVak between the cathode electrode 18 and the anode electrode 14 at the peak time point P1 at which is performed is within 20V (about 10V in the example of FIG. 11B) and hardly changes. Therefore, there is almost no generation of positive ions, damage to the cathode electrode 18 due to positive ions can be prevented, which is advantageous in extending the life of the electron-emitting device 10A.
[0069]
Here, the dielectric breakdown voltage of the emitter section 16 is preferably at least 10 kV / mm. In this example, when the thickness d of the emitter portion 16 is set to 20 μm, for example, even if a drive voltage of −100 V is applied between the cathode electrode 18 and the anode electrode 14, the emitter portion 16 does not cause dielectric breakdown.
[0070]
By the way, electrons emitted from the emitter section 16 collide with the emitter section 16 again, or ionization near the surface of the emitter section 16 damages the emitter section 16 to induce crystal defects. May become brittle.
[0071]
Therefore, it is preferable that the emitter section 16 is made of a dielectric material having a high evaporation temperature in vacuum, for example, BaTiO not containing Pb._ThreeYou may make it comprise by these. Thereby, the constituent atoms of the emitter section 16 are less likely to evaporate due to Joule heat, and the promotion of ionization by electrons can be prevented. This is effective in protecting the surface of the emitter section 16.
[0072]
Further, the electric field distribution between the emitter section 16 and the collector electrode 22 can be changed by appropriately changing the pattern shape and potential of the collector electrode 22 or by arranging a control electrode (not shown) between the emitter section 16 and the collector electrode 22. By arbitrarily setting, it becomes easy to control the emission trajectory of secondary electrons, and the convergence, expansion, and deformation of the electron beam diameter are also facilitated.
[0073]
The above-described realization of an electron source with high linearity and ease of control of the secondary electron emission trajectory are obtained when the electron-emitting device 10A according to the first embodiment is configured as a pixel of a display. This is advantageous for narrowing the pitch.
[0074]
As described above, in the electron-emitting device 10A according to the first embodiment, since the secondary electrons emitted from the emitter section 16 are output, it is possible to extend the life of the electron emission and improve the reliability. it can. This leads to the fact that the electron-emitting device 10A according to the first embodiment can be applied to various applications, and can contribute to the spread of the electron-emitting device 10A.
[0075]
In the above example, the collector electrode 22 is formed on the back surface of the transparent plate 21, and the phosphor 24 is formed on the surface of the collector electrode 22 (the surface facing the cathode electrode 18). Like the electron-emitting device 10Ad according to the fourth modification, the phosphor 24 may be formed on the back surface of the transparent plate 21, and the collector electrode 22 may be formed so as to cover the phosphor 24.
[0076]
This is a configuration used in a CRT or the like, and the collector electrode 22 functions as a metal back. The secondary electrons emitted from the emitter section 16 penetrate the collector electrode 22 and enter the phosphor 24 to excite the phosphor 24. Therefore, the collector electrode 22 is thick enough to allow secondary electrons to pass through, and is preferably 100 nm or less. The greater the kinetic energy of the secondary electrons, the thicker the collector electrode 22 can be made.
[0077]
With such a configuration, the following effects can be obtained.
[0078]
(1) When the phosphor 24 is not conductive, charging (negative) of the phosphor 24 can be prevented and an acceleration electric field of secondary electrons can be maintained.
[0079]
(2) The collector electrode 22 reflects the light emitted from the phosphor 24, and the light emitted from the phosphor 24 can be efficiently emitted to the transparent plate 21 side (light emitting surface side).
[0080]
(3) Excessive collision of secondary electrons with the phosphor 24 can be prevented, and deterioration of the phosphor 24 and generation of gas from the phosphor 24 can be prevented.
[0081]
Next, an electron emitter 10B according to a second embodiment will be described with reference to FIG.
[0082]
As shown in FIG. 13, the electron-emitting device 10B according to the second embodiment has substantially the same configuration as the electron-emitting device 10A according to the first embodiment described above. The anode electrode 14 is formed on the substrate 12, the emitter section 16 is formed on the substrate 12 so as to cover the anode electrode 14, and the cathode electrode 18 is formed on the emitter section 16. It is different in point.
[0083]
Also in this case, similarly to the electron-emitting device 10A according to the first embodiment described above, damage to the cathode electrode 18 due to positive ions can be prevented, which is advantageous in extending the life of the electron-emitting device 10B.
[0084]
In addition, as a method of forming the emitter section 16 on the substrate 12, various thick film forming methods such as a screen printing method, a dipping method, a coating method, an electrophoresis method, an ion beam method, a sputtering method, a vacuum evaporation method, Various thin film forming methods such as ion plating, chemical vapor deposition (CVD), and plating can be used.
[0085]
In the second embodiment, in forming the emitter section 16, a thick film forming method such as a screen printing method, a dipping method, a coating method, or an electrophoresis method is preferably employed.
[0086]
These methods can be formed using pastes or slurries, or suspensions, emulsions, sols, or the like mainly composed of piezoelectric ceramic particles having an average particle diameter of 0.01 to 5 μm, preferably 0.05 to 3 μm. This is because good piezoelectric operation characteristics can be obtained.
[0087]
In particular, the electrophoretic method is capable of forming a film with high density and high shape accuracy, as well as “electrochemistry and industrial physical chemistry Vol. 53, No. 1 (1985), p 63-68 Kazuo Anzai. The authors have the characteristics described in the technical literature such as “Hirotsu” or “The 1st Electrophoresis Method for High-Order Forming of Ceramics Research Discussion (1998), p5-6, p23-24”. Alternatively, a piezoelectric / electrostrictive / antiferroelectric material formed into a sheet shape, a laminate thereof, or a laminate or adhesion of these to another support substrate may be used. As described above, it is preferable to select and use a method as appropriate in consideration of required accuracy and reliability.
[0088]
The substrate 12 is preferably made of an electrically insulating material in consideration of wiring and the like. Therefore, the substrate 12 can be made of glass, a high heat-resistant metal, or a material such as enamel whose metal surface is coated with a ceramic material such as glass, but it is optimal to make it with ceramics. .
[0089]
As the ceramic constituting the substrate 12, for example, stabilized zirconium oxide, aluminum oxide, magnesium oxide, titanium oxide, spinel, mullite, aluminum nitride, silicon nitride, glass, a mixture thereof, or the like can be used. Among these, aluminum oxide and stabilized zirconium oxide are preferable from the viewpoint of strength and rigidity. Stabilized zirconium oxide is particularly suitable from the viewpoints of relatively high mechanical strength, relatively high toughness, and relatively small chemical reaction with the cathode electrode 18 and the anode electrode 14. The stabilized zirconium oxide includes stabilized zirconium oxide and partially stabilized zirconium oxide. Stabilized zirconium oxide has a cubic crystal structure or the like and therefore does not cause phase transition.
[0090]
On the other hand, zirconium oxide undergoes a phase transition between a monoclinic crystal and a tetragonal crystal at around 1000 ° C., and cracks may occur during such a phase transition. Stabilized zirconium oxide contains 1 to 30 mol% of a stabilizer such as calcium oxide, magnesium oxide, yttrium oxide, scandium oxide, ytterbium oxide, cerium oxide, and rare earth metal oxides. In order to improve the mechanical strength of the substrate 12, the stabilizer preferably contains yttrium oxide. In this case, yttrium oxide is preferably contained in an amount of 1.5 to 6 mol%, more preferably 2 to 4 mol%, and further preferably 0.1 to 5 mol% of aluminum oxide.
[0091]
The crystal phase can be a cubic + monoclinic mixed phase, a tetragonal + monoclinic mixed phase, a cubic + tetragonal + monoclinic mixed phase, and the like. A phase having a tetragonal crystal or a mixed phase of tetragonal crystal + cubic crystal is optimal from the viewpoint of strength, toughness and durability.
[0092]
When the substrate 12 is made of ceramics, a relatively large number of crystal grains constitute the substrate 12. In order to improve the mechanical strength of the substrate 12, the average grain size of the crystal grains is preferably 0.05. ˜2 μm, more preferably 0.1-1 μm.
[0093]
Each time the emitter section 16, the cathode electrode 18 and the anode electrode 14 are formed, a heat treatment (firing process) can be performed to form an integral structure with the substrate 12, and the emitter section 16, the cathode electrode 18, and the anode electrode 14 can be combined. After the formation, they can be fired at the same time, and these can be integrally bonded to the substrate 12 at the same time. Depending on the method of forming the cathode electrode 18 and the anode electrode 14, a heat treatment (firing process) for integration may not be required.
[0094]
The temperature related to the baking treatment for integrating the substrate 12, the emitter section 16, the cathode electrode 18, and the anode electrode 14 is in the range of 500 to 1400 ° C, and preferably in the range of 1000 to 1400 ° C. . Further, when the film-shaped emitter portion 16 is heat-treated, it is preferable to perform a firing process while controlling the atmosphere together with the evaporation source of the emitter portion 16 so that the composition of the emitter portion 16 does not become unstable at high temperatures.
[0095]
Alternatively, a method may be employed in which the emitter portion 16 is covered with an appropriate member and fired so that the surface of the emitter portion 16 is not directly exposed to the firing atmosphere. In this case, it is preferable to use the same material as the substrate 12 as the covering member.
[0096]
Next, an electron-emitting device 10C according to a third embodiment will be described with reference to FIGS. 14 to 17B.
[0097]
As shown in FIG. 14, the electron-emitting device 10C according to the third embodiment has substantially the same configuration as the electron-emitting device 10B according to the second embodiment described above, but the cathode electrode 18 and the anode electrode 14 is formed on one surface of the emitter section 16 and is different in that a slit 26 is formed between the cathode electrode 18 and the anode electrode 14.
[0098]
In the electron-emitting device 10C according to the third embodiment, the electric field concentration points A and B exist, but the point A has a triple point where the cathode electrode 18 / emitter portion 16 / vacuum exists at one point. The point B can also be defined as a point including a triple point where the anode electrode 14 / emitter 16 / vacuum exists at one point.
[0099]
Here, the size of the width W of the slit 26 between the cathode electrode 18 and the anode electrode 14 will be described. When the voltage between the cathode electrode 18 and the anode electrode 14 is Vak, the electric field represented by E = Vak / W. The width W is preferably set so that polarization inversion is performed at E. That is, as the width W of the slit 26 is smaller, polarization inversion can be performed at a low voltage, and electrons can be emitted by driving at a low voltage (for example, less than 100 V).
[0100]
Regarding the dimensions of the cathode electrode 18, as shown in FIG. 15, the width W1 was 2 mm and the length L1 was 5 mm. The thickness of the cathode electrode 18 is preferably 20 μm or less, and preferably 5 μm or less.
[0101]
The thickness of the anode electrode 14 is also preferably 20 μm or less, and preferably 5 μm or less. As for the dimensions of the anode electrode 14, as shown in FIG. 15, the width W2 was set to 2 mm and the length L2 was set to 5 mm as in the cathode electrode 18.
[0102]
In addition, the width W of the slit 26 between the cathode electrode 18 and the anode electrode 14 is set to 70 μm in the third embodiment.
[0103]
Next, the principle of electron emission of the electron-emitting device 10C will be described with reference to FIGS. 6, 14, and 16 to 17B. Also in the third embodiment, as shown in FIG. 6, as in the first embodiment described above, the period during which the first voltage Va1 is output (preparation period T1) and the second voltage Va2 are output. Is a step (electron emission period T2), and the one step is repeated.
[0104]
First, in the preparation period T1, as shown in FIG. 16, when the first voltage Va1 is applied between the cathode electrode 18 and the anode electrode 14, the emitter section 16 is polarized in one direction. Also in this case, the first voltage Va1 may be a DC voltage as shown in FIG. 6, but one pulse voltage or a pulse voltage may be continuously applied a plurality of times. The preparation period T1 is preferably longer than the electron emission period T2 in order to sufficiently perform the polarization process. For example, the preparation period T1 is preferably 100 μsec or more.
[0105]
Thereafter, in the electron emission period T2, by applying the second voltage Va2 between the cathode electrode 18 and the anode electrode 14, as shown in FIG. 17A, at least a part of the emitter part 16 (a part exposed from the slit 26). ) Is inverted. Due to this polarization reversal, a local concentrated electric field is generated between the cathode electrode 18 and the positive pole side of the dipole moment in the vicinity thereof, whereby primary electrons are drawn from the cathode electrode 18 and drawn from the cathode electrode 18. Primary electrons collide with the emitter section 16 and secondary electrons are emitted from the emitter section 16.
[0106]
As described above, in the electron-emitting device 10C according to the third embodiment, similarly to the electron-emitting device 10A according to the first embodiment described above, the lifetime of the electron emission is increased and the reliability is improved. Can be applied to various applications.
[0107]
By the way, the electrons drawn to the anode electrode 14 ionize mainly the gas existing in the vicinity of the anode electrode 14 or the atoms constituting the anode electrode 14 into positive ions and electrons. The atoms constituting the anode electrode 14 present in the vicinity of the anode electrode 14 are atoms generated as a result of evaporation of a part of the anode electrode 14, and the atoms are floating in the vicinity of the anode electrode 14. Then, since the electrons generated by the ionization further ionize the gas, the atoms, and the like, the number of electrons increases exponentially, and when this proceeds and the electrons and positive ions exist neutrally, a local plasma is formed.
[0108]
Further, the electrons drawn to the anode electrode 14 collide with the emitter section 16 and secondary electrons are emitted from the emitter section 16, and the gas existing in the vicinity of the anode electrode 14 or the vicinity of the anode electrode 14 as described above. Electrode atoms transpiration and floating in are ionized into positive ions and electrons.
[0109]
The positive ions generated by the ionization may collide with the cathode electrode 18, for example, which may damage the cathode electrode 18.
[0110]
Therefore, in the electron-emitting device 10Ca according to the modification shown in FIG. 18, the charging film 28 is formed on the surface of the anode electrode 14.
[0111]
Therefore, when a part of the secondary electrons emitted from the emitter section 16 is attracted to the anode electrode 14, the surface of the charging film 28 is negatively charged as shown in FIG. As a result, the positive polarity of the anode electrode 14 is weakened, the electric field strength E between the anode electrode 14 and the cathode electrode 18 is reduced, and ionization stops instantaneously. That is, as the driving voltage Va applied between the cathode electrode 18 and the anode electrode 14, as shown in FIG. 19A, when the first voltage Va1 is set to +50 V, for example, and the second voltage Va2 is set to −100 V, for example, FIG. As shown in FIG. 6, the voltage change ΔVak between the cathode electrode 18 and the anode electrode 14 at the peak time point P1 when the electron emission is performed is within 20 V (about 10 V in the example of FIG. 19B) and hardly changes. Therefore, there is almost no generation of positive ions, damage to the cathode electrode 18 due to positive ions can be prevented, which is advantageous in extending the life of the electron-emitting device 10Ca.
[0112]
The thickness t1 of the charging film 28 formed on the surface of the anode electrode 14 is preferably 10 nm to 100 μm. If it is too thin, there is a risk of problems in durability and handling. If it is too thick, the distance between the cathode electrode 18 and the anode electrode 14, that is, the width W of the slit cannot be reduced, and an electric field necessary for electron emission is obtained. This is because there is a risk that it will not be possible. In this modification, the thickness t1 of the charging film 28 is 45 μm.
[0113]
The charged film 28 can be composed of a piezoelectric material, an electrostrictive material, an antiferroelectric material, or a low dielectric constant material. As a low dielectric constant material, for example, SiO₂An oxide such as MgO or glass or glass can be used. Of course, the charging film 28 may be made of the same material as that of the dielectric constituting the emitter section 16.
[0114]
The electron-emitting device 10C (including the modification) according to the third embodiment includes the electron-emitting device 10A (including the modification) according to the first embodiment and the electron-emitting device according to the second embodiment. When compared with 10B, the form relating to polarization reversal of the emitter section 16 in the vicinity of the cathode electrode 18 is different. The electron-emitting devices 10A and 10B according to the first and second embodiments are formed between the cathode electrode 18 because the dipole moment that appears on the cathode electrode 18 side is only positive or negative. A large local electric field can be taken. On the other hand, the electron-emitting device 10 </ b> C according to the third embodiment has an advantage that electrodes need only be formed on one main surface of the emitter section 16.
[0115]
Further, the electron-emitting devices 10A and 10B according to the first and second embodiments have a positive polarity of a dipole moment in the vicinity of the cathode electrode 18 when the cathode electrode 18 becomes negative at the time of polarization reversal of the emitter section. Can only be placed. Therefore, it is preferable for extracting primary electrons from the cathode electrode 18.
[0116]
Thus, the electron-emitting device 10A according to the first embodiment (including the electron-emitting devices 10Aa to 10Ad according to the first to fourth modifications), the electron-emitting device 10B according to the second embodiment, and In the electron-emitting device 10C according to the third embodiment (including the electron-emitting device 10Ca according to the modification), in addition to the use as a display, an electron beam irradiation device, a light source, an alternative use of an LED, and an electronic component manufacturing device Can be applied to.
[0117]
The electron beam in the electron beam irradiation apparatus has high energy and excellent absorption performance as compared with the ultraviolet light in the currently widely used ultraviolet irradiation apparatus. As application examples, in semiconductor devices, there are uses for solidifying insulating films when stacking wafers, uses for curing printing inks uniformly when printing is dried, and uses for sterilizing medical devices in packages. .
[0118]
The use as a light source is for high luminance and high efficiency specifications, for example, a light source use of a projector in which an ultra-high pressure mercury lamp or the like is used. When the electron-emitting devices 10A (10Aa to 10Ad), 10B, and 10C (10Ca) are applied to the light source, they have characteristics of downsizing, long life, high-speed lighting, and reduction of environmental load due to mercury-free.
[0119]
Alternative uses of LEDs include surface light source applications such as indoor lighting, automotive lamps, and traffic lights, and chip light sources, traffic lights, and backlights for small liquid crystal displays for mobile phones.
[0120]
Applications of the electronic component manufacturing apparatus include an electron beam source of a film forming apparatus such as an electron beam vapor deposition apparatus, an electron source for plasma generation (for activation of gas, etc.) in a plasma CVD apparatus, an electron source for gas decomposition application, etc. . In addition, there are vacuum microdevice applications such as terahertz drive high-speed switching elements and large current output elements. In addition, it is also preferably used as a printer component, that is, a light emitting device for exposing a photosensitive drum or an electron source for charging a dielectric.
[0121]
As electronic circuit components, a large current output and a high amplification factor are possible, and therefore there are applications to digital elements such as switches, relays, and diodes, and analog elements such as operational amplifiers.
[0122]
In addition, in the electron-emitting devices 10A (10Aa to 10Ad), 10B, and 10C (10Ca), as shown in FIG. Such effects can be achieved.
[0123]
(1) It can be made ultra-thin (panel thickness = several mm) as compared with CRT.
[0124]
(2) Due to spontaneous light emission by the phosphor 24, a wide viewing angle of approximately 180 ° can be obtained as compared with LCD (Liquid Crystal Display) and LED (Light Emitting Diode).
[0125]
(3) Since a surface electron source is used, there is no image distortion as compared with a CRT.
[0126]
(4) High-speed response is possible as compared with LCD, and moving image display without afterimage is possible with a high-speed response on the order of μsec.
[0127]
(5) It is about 100 W in terms of 40 inches, and consumes less power than CRT, PDP (plasma display), LCD and LED.
[0128]
(6) Wide operating temperature range (-40 to + 85 ° C) compared to PDP and LCD. Incidentally, the response speed of the LCD decreases at low temperatures.
[0129]
(7) Since the phosphor can be excited by a large current output, the brightness can be increased as compared with a conventional FED display.
[0130]
(8) Since the driving voltage can be controlled by the polarization reversal characteristics and film thickness of the piezoelectric material, it can be driven at a lower voltage than a conventional FED display.
[0131]
From such various effects, various display applications can be realized as described below.
[0132]
(1) It is most suitable for 30-60 inch display home use (television, home theater) and public use (waiting room, karaoke, etc.) in terms of realizing high brightness and low power consumption.
[0133]
(2) From the aspect that high brightness, large screen, full color, and high definition can be realized, it has a great effect on customer attraction (in this case, visual attention). Ideal for use in exhibitions, message boards for information guides.
[0134]
(3) It is most suitable for in-vehicle displays from the viewpoint that high brightness, a wide viewing angle accompanying phosphor excitation, and a wide operating temperature range associated with vacuum modularization can be realized. The specifications for the in-vehicle display are: 8 inches wide (pixel pitch: 0.14 mm) such as 15: 9, operating temperature of -30 to + 85 ° C., 500 to 600 cd / m in the perspective direction.²is required.
[0135]
In addition, from the various effects described above, various light source applications can be realized as described below.
[0136]
(1) From the standpoint that high luminance and low power consumption can be realized, it is most suitable for a light source for a projector that requires 2000 lumens as a luminance specification.
[0137]
(2) A high-brightness two-dimensional array light source can be easily realized, the operating temperature range is wide, and the luminous efficiency does not change even in an outdoor environment, so it is promising as an alternative application for LEDs. For example, it is optimal as an alternative to a two-dimensional array LED module such as a traffic light. Note that the LED has a lower allowable current at a temperature of 25 ° C. or higher and low luminance.
[0138]
It should be noted that the electron-emitting device and the light-emitting device according to the present invention are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention.
[0139]
【The invention's effect】
As described above, according to the electron-emitting device and the light-emitting device according to the present invention, the output of secondary electrons emitted from the substance serving as the emitter can increase the lifetime of the electron emission and improve the reliability. Can be planned. Further, it can be applied to various applications and can contribute to the spread of electron-emitting devices.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an electron-emitting device according to a first embodiment.
FIG. 2 is a plan view showing an electrode portion of the electron-emitting device according to the first embodiment.
FIG. 3 is a plan view showing an electrode portion in a first modification of the electron-emitting device according to the first embodiment.
FIG. 4 is a plan view showing an electrode portion in a second modification of the electron-emitting device according to the first embodiment.
FIG. 5 is a configuration diagram showing a third modification of the electron-emitting device according to the first embodiment.
FIG. 6 is a waveform diagram showing a drive voltage output from a pulse generation source.
FIG. 7 is an explanatory diagram showing an operation when a first voltage is applied between a cathode electrode and an anode electrode in the first embodiment.
FIG. 8 is an explanatory diagram showing an electron emission action when a second voltage is applied between a cathode electrode and an anode electrode.
FIG. 9 is an explanatory diagram showing the action of self-stopping of electron emission accompanying negative charging on the surface of the emitter section.
FIG. 10 is a characteristic diagram showing the relationship between the energy of emitted secondary electrons and the emission amount of secondary electrons.
11A is a waveform diagram illustrating an example of a drive voltage, and FIG. 11B is a waveform diagram illustrating a change in voltage between an anode electrode and a cathode electrode in the electron-emitting device according to the first embodiment. is there.
FIG. 12 is a configuration diagram showing a fourth modification of the electron-emitting device according to the first embodiment.
FIG. 13 is a configuration diagram showing an electron-emitting device according to a second embodiment.
FIG. 14 is a configuration diagram showing an electron-emitting device according to a third embodiment.
FIG. 15 is a plan view showing an electrode portion of an electron-emitting device according to a third embodiment.
FIG. 16 is an explanatory diagram showing an operation when a first voltage is applied between a cathode electrode and an anode electrode in the third embodiment.
FIG. 17A is an explanatory diagram showing an action (emission of primary electrons) when a second voltage is applied between the cathode electrode and the anode electrode, and FIG. 17B shows the emitted primary electrons; It is explanatory drawing which shows the principle in which a secondary electron is discharge | released based on.
FIG. 18 is an explanatory diagram showing an operation when a second voltage is applied between a cathode electrode and an anode electrode in a modification of the electron-emitting device according to the third embodiment.
FIG. 19A is a waveform diagram showing an example of a drive voltage, and FIG. 19B shows a change in voltage between the cathode electrode and the anode electrode in a modification of the electron-emitting device according to the first embodiment. It is a waveform diagram.
[Explanation of symbols]
10A, 10Aa to 10Ad, 10B, 10C, 10Ca ... electron-emitting device
12 ... Substrate 14 ... Anode electrode
16 ... Emitter 18 ... Cathode electrode
20 ... Pulse generation source 22 ... Collector electrode
24 ... phosphor

Claims (10)

A substance to be an emitter composed of a dielectric;
A first electrode formed on the emitter material;
A second electrode formed on the material to be the emitter,
An electron-emitting device that emits electrons by applying a driving voltage between the first electrode and the second electrode so that at least a part of the substance serving as the emitter is inverted in polarization,
The first electrode and the second electrode are formed on the same surface of the substance to be the emitter,
By applying the drive voltage between the first electrode and the second electrode, at least a part of the substance that becomes the emitter is inverted in polarity, and the polarization inversion causes the periphery of the first electrode. By arranging the positive pole side of the dipole moment, primary electrons are extracted from the first electrode, and the primary electrons extracted from the first electrode collide with the substance serving as the emitter, and the emitter An electron-emitting device having a driving voltage applying means for emitting secondary electrons from a material to be obtained. In the electron-emitting device according to Claim 1 Symbol placement,
An electron-emitting device, wherein an electron beam is obtained by accelerating secondary electrons emitted from the emitter material by an electric field formed on the emitter material. The electron-emitting device according to claim 1 or 2 ,
The electron-emitting device according to claim 1, wherein the emitter substance is any one of a piezoelectric material, an antiferroelectric material, and an electrostrictive material. The electron-emitting device according to any one of claims 1 to 3 ,
When the distance between the first electrode and the second electrode is d, and the voltage between the first electrode and the second electrode is Vak, it is applied to the substance serving as the emitter, and E = An electron-emitting device, wherein polarization inversion is performed by an electric field E expressed by Vak / d. The electron-emitting device according to claim 4 .
The electron-emitting device, wherein the voltage Vak is less than a dielectric breakdown voltage of the substance serving as the emitter. The electron-emitting device according to claim 4 or 5 ,
The distance d between the first electrode and the second electrode is set so that the absolute value of the voltage Vak between the first electrode and the second electrode is less than 100V. Electron-emitting device. The electron-emitting device according to any one of claims 1 to 6 ,
When the drive voltage is applied between the first electrode and the second electrode, at least a part of the substance that becomes the emitter is inverted in polarity, and the potential is lower than that of the second electrode. An electron-emitting device, wherein the primary electrons are emitted from the vicinity of the electrode. The electron-emitting device according to any one of claims 1 to 7 ,
The first electrode, the substance to be the emitter and a triple point of a vacuum atmosphere,
Of the first electrode, the primary electrons are extracted from a portion near the triple point,
The electron-emitting device characterized in that the extracted primary electrons collide with the substance that becomes the emitter, and the secondary electrons are emitted from the substance that becomes the emitter. The electron-emitting device according to any one of claims 1 to 8 ,
A third electrode for forming an electric field between the substance serving as the emitter and the substance serving as the emitter is disposed, and an electron beam is emitted to the third electrode. Emitting element. The electron-emitting device according to any one of claims 1 to 9 ,
An electrode for forming an electric field between the electron-emitting device and the substance serving as the emitter;
A phosphor formed on the electrode,
A light-emitting element that emits light by exciting secondary phosphors that collide with secondary phosphors emitted from a substance that serves as the emitter.

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